Extruded sections, particularly of plastic or aluminum, as well as roll formed plastic, aluminum and other sheet metal profiles enjoy widespread use, due to their weight advantage and ready availability. In their use, for fabricating sliding or rolling patio doors for instance, the joining of the corners for the assembly and disassembly of a high quality aluminum product entail the use of threaded fasteners which are labour intensive. Furthermore, the capability of unwarranted or accidental disassembly always exists, which is not necessarily desirable.